Last week’s forecast didn’t turn out exactly as predicted, but it wasn’t due to a lack of trying by Mother Nature. The broad area of low pressure formed to our west as predicted and we did see some low to even mid-20s for highs late last week. Then a weak cold front moved through our region over the weekend dropping temperatures a little bit and keeping the really warm air off to our west.
For this forecast period it looks like we’ll start off with pleasant early- to mid-May weather with plenty of sunshine and slightly cooler temperatures. The cooler weather is thanks in part to the large storm system that brought the heavy rains to Eastern Canada last week. The remnant upper low associated with this system is forecast to do a retrograde loop; this will help to bring cooler air into our region. Expect daytime highs to be in the 10 to 15 C range with overnight lows a few degrees above 0 C.
It looks like we will be in a predominantly northwesterly flow right through the weekend. With weak high pressure in place, most days will start off sunny, but will transition to scattered afternoon clouds. Expect daytime highs to slowly inch up a degree or so each day, pushing the 20 C mark by Saturday or Sunday.
By early next week the weather models are showing a large area of arctic high pressure building southward. It is forecast to move fairly slowly, with some weather models sliding the high to our east while others have it coming right over the top of us by the middle of next week. The exact track of this high will impact our temperatures, with a more easterly track resulting in milder conditions. While we might see a bit of a cool-down initially with this high, the strong late-spring sunshine should help to warm things up, with daytime highs expected to be in the upper teens to low 20s. Overnight lows will be on the cool side, so don’t jump the gun with any outdoor planting!
Usual temperature range for this period: Highs, 11 to 25 C; lows, -1 to +9 C.